The present invention relates to a device for production of a beverage by infusion and a coffee machine equipped with such a device.
The invention will be applied in the manufacture of coffee machines of the type used to produce individual beverages, or in larger quantities for hotel or professional use. In particular, the invention applies to coffee machines using ground coffee in the form of ready-to-use prepackaged doses, also called capsules or “pods”, such as envisaged in document WO-A-95/07041.
Document U.S. Pat. No. 5,312,637 concerning a coffee machine with an infusion chamber and a circuit for injecting hot water through the infusion chamber is known. The beverage thus produced by infusion is evacuated through an outlet. Moreover, this document describes a return circuit for the beverage from the outlet part to the inlet of the chamber in order to carry out several successive infusions.
A disadvantage of the machine according to this former technology is that the quality of the extracted liquid declines considerably after the first passage of liquid through the infusion chamber. As a result, recirculation is not very effective for extracting all the flavors contained in the ground product.
The present invention overcomes this disadvantage and to do this describes a device for the producing beverages and an improved coffee machine.
To do this, according to the invention, hot water can be circulated through the infusion chamber in both directions. This inversion ensures that hot water running into the infusion chamber is better distributed so as to extract the maximum amount of the aromatic components.
It will be noted that in the existing devices, and in particular the one covered by U.S. Pat. No. 5,312,637, ground coffee has a strong tendency to compact after the first passage of water, and this even more so as the extraction pressure increases.
Moreover, when first circulated in the infusion chamber, water has a tendency to create a preferred path (in particular following the distribution of the ground product in the chamber, along the edges of the chamber, and the point(s) at which the water is injected into the infusion chamber). The path followed by the water on its first passage tends to be repeated during the next passage.
On the contrary, the present invention avoids this tendency so that the passage of water is better distributed through the infusion chamber.
This optimizes the extraction which can be faster and allow the delivery of the maximum flavors contained in the ground product.
Other aims and advantages will appear during the description of a preferred embodiment which follows, which is however not restrictive.